They can already stand, walk, wriggle under obstacles, and change colors. Now researchers are adding a new skill to the soft robot arsenal: jumping.
Using small explosions produced by a mix of methane and oxygen, researchers at Harvard have designed a soft robot that can leap as much as a foot in the air. That ability to jump could one day prove critical in allowing the robots to avoid obstacles during search and rescue operations. The research is described in a Feb. 6 paper in the international edition of Angewandte Chemie.
"Initially, our soft robot systems used pneumatic pressure to actuate," said Robert Shepherd, first author of the paper, former postdoctoral researcher in the Whitesides Research Group at Harvard, and now an assistant professor at Cornell. "While that system worked, it was rather slow — it took on the order of a second. Using combustion, however, allows us to actuate the robots very fast. We were able to measure the speed of the robot's jump at 4 meters per second."
Just as with other soft robots, the three-legged jumping system begins life as a mold created by a 3-D printer. The robots are molded using soft silicone that allows them to stretch and flex.
But where pneumatic robots are connected to tubing that pumps air, the jumping robots are connected to tubes that deliver a precisely controlled mix of methane and oxygen. Using high-voltage wires embedded in each leg of the robot, researchers deliver a spark to ignite the gases, causing a small explosion that sends the robot into the air.
Among the key design innovations that allowed the combustion system to work, Shepherd said, was the incorporation of a simple valve into each leg of the robot.
"We flow fuel and oxygen into the channels, and ignite it," Shepherd said. "The heat expands the gas, causing the flap to close, pressurizing the channel and causing it to actuate. As the gas cools, the flap opens and we push the exhaust out by flowing more gas in. So we don't need to use complex valve systems, all because we chose to mold a soft flap into the robot from the beginning."
While the notion of using combustion to power a soft robot was enticing, it also came with a number of critical questions, not the least of which was whether the soft silicone used to create the robots would even survive.
"It's a lot more powerful, but the question we had to answer was whether it was compatible — were the temperatures compatible — with this system," Shepherd said. "What we were able to show is, because the duration of the explosion is so short, the energies absorbed by the robot are small enough to be compatible with soft robots. What's more, the temperature of the robot increases by, on average, less than one kelvin."
While he hopes to see internal combustion systems developed that can allow robots to walk or even run, Shepherd said jumping made sense as a starting point."Because it releases so much energy so fast, it made sense for jumping to be the first 'gait' we explored with this system," he said. "The next step now is to learn how we can use this combustion system for other gaits, like running or even walking."
Other authors on the paper are Adam Stokes, Jacob Freake, Phillip Snyder, Aaron Mazzeo, Ludovico Cademartiri, Stephen A. Morin, George M. Whitesides, the Woodford L. and Ann A. Flowers University Professor at Harvard, and Jabulani Barber, an FAS research associate with the Whitesides Research Group.
Peter Reuell | EurekAlert!
Harvesting the Sun for Power and Produce
24.11.2017 | Fraunhofer-Institut für Solare Energiesysteme ISE
Batteries with better performance and improved safety
23.11.2017 | Empa - Eidgenössische Materialprüfungs- und Forschungsanstalt
High-precision measurement of the g-factor eleven times more precise than before / Results indicate a strong similarity between protons and antiprotons
The magnetic moment of an individual proton is inconceivably small, but can still be quantified. The basis for undertaking this measurement was laid over ten...
Heat from the friction of rocks caused by tidal forces could be the “engine” for the hydrothermal activity on Saturn's moon Enceladus. This presupposes that...
The WHO reports an estimated 429,000 malaria deaths each year. The disease mostly affects tropical and subtropical regions and in particular the African continent. The Fraunhofer Institute for Silicate Research ISC teamed up with the Fraunhofer Institute for Molecular Biology and Applied Ecology IME and the Institute of Tropical Medicine at the University of Tübingen for a new test method to detect malaria parasites in blood. The idea of the research project “NanoFRET” is to develop a highly sensitive and reliable rapid diagnostic test so that patient treatment can begin as early as possible.
Malaria is caused by parasites transmitted by mosquito bite. The most dangerous form of malaria is malaria tropica. Left untreated, it is fatal in most cases....
The formation of stars in distant galaxies is still largely unexplored. For the first time, astron-omers at the University of Geneva have now been able to closely observe a star system six billion light-years away. In doing so, they are confirming earlier simulations made by the University of Zurich. One special effect is made possible by the multiple reflections of images that run through the cosmos like a snake.
Today, astronomers have a pretty accurate idea of how stars were formed in the recent cosmic past. But do these laws also apply to older galaxies? For around a...
Just because someone is smart and well-motivated doesn't mean he or she can learn the visual skills needed to excel at tasks like matching fingerprints, interpreting medical X-rays, keeping track of aircraft on radar displays or forensic face matching.
That is the implication of a new study which shows for the first time that there is a broad range of differences in people's visual ability and that these...
15.11.2017 | Event News
15.11.2017 | Event News
30.10.2017 | Event News
24.11.2017 | Physics and Astronomy
24.11.2017 | Health and Medicine
24.11.2017 | Earth Sciences